Interlocking system for railroads



Sept. 22, 1931. s. N. WIGHT 1,824,181

INTERLOCKING SYSTEM FOR RAILROADS Filed July 18, 1929 ATTORNEY 1 1 Patented Sept. 22, 1931 UNITED STATES PATENT, oFFicE-c SEDGWICK N. WIGHT, OF ROCHESTER, NEXV YORK, ASSIGNOR TO GENERAL RAILWAY I SIGNAL CQMPAN Y, OF ROCHESTER, NEW YORK INTERLOCKING SYSTEM FOR RAILROADS This invention relates to interlocking systems, and more particularly to a novel interlocking system in which all of the interlocking is carried on directly between traflic controlling devices rather than between levers controlling such traffic controlling devices.

As understoodby those skilled in the art of interlocking practice, it is essential that no traflic controlling device should be permitted to assume a particular indicating or control condition unless all conflictable trafiic controlling devices are in a non-conflicting condition. In mechanical interlocking plants it is found expedient to have the interlocking mechanism associated with the levers, this for mechanical and structural reasons. During the evolution'of interlocking practice this theory of interlocking levers mechanically has been carried on to interlocking plants employing electrically controlled traflic controlling devices.

Inaccordance with the present invention itis proposed to leave the control levers free for movement in any direction at all times, and to so interlock the circuits controlledcby these levers, through contacts controlled by the various traffic controlling devices, that it is impossible to supply clearing or operating energy to any particular trafiic controlling device unless all of the conflictable traflic controlling devices have been operated to their non-cnflicting positions or conditions. 3

Another object of the present invention resides in the provision of means for indicating in the tower if a particular traflic controlling device cannot be operated by reason of the fact that thereis a conflictable traflic controlling device in its conflicting position or condition. 7

Other objects purposes and characteristic features of the invention will in part be described hereinafter and in part be obvious from the accompanying drawing.

' In describing the invention in detail reference will be made to the accompanying drawing which conventionally shows the control circuits and devices at a particular way station together with a lever and indiciifiting apparatus located in the dispatchers 0 cc. I

Referring to the drawing the main track of a railway system has been shown by track rails 1 divided into track sections by insulatingjoints 2, of whichthe track sections A, B and C only have been shown. From; this main track diverge the routes D andE, comprising rails 3 and 4 respectively. Each of these track sections is provided with the usual track circuit, of which the track section A has a track circuit including the battery 5 and the track relay T, the track circuit of section 13' includes the track relay T and the battery 6, the track section C has a track circuit including the battery '7 and the track relay T and the track circuit of section E contains the track relay T and the track battery 8.

The diverging route E is connected tothe main track through themediumof the track switch S and the diverging route D is connected to the main track through the medium of the track switch S At the entrance to the diverging route E is located a main signal ME and a take-siding signal DE, whereas at the entrance to the diverging route D there is located a main west-bound signal MW. The switches S and S are provided withthe usual switch box contacts, which contacts are included in the interlocking circuits more clearly described in connection with the operation of the system. Also,'if desired, these switches S and S may be operated by-switch machines controlled by control relays and indicatingtrack circuit occupancy in a manner as shown in the ap- 'plication of F. L. Dodgson, Ser. N 0, 187,508, filed April 29, 1927.

In the interlocking tower, theentire interlocking plant or plants are preferably rethe system will be best understood by con sidering the operation. of the system..

Ofaemti'oa.Althougli. the switches S and S may be either hand-operated from a local switch stand, they may be operated from theinterlocking tower either mechanically or electrically, it is for convenience assumed;

that these track switches are operated from the dispatchers office by mechanical means such as'pi'pe lines'or cables.

Let us. assume that both of these track switches S and S assume the main" track position. Let us further assume that the operator wishes to clear the main signal ME. In order todo so the operator will operate the lever L to its dotted proceed position, thereby completing the following circuit beginning at the towerbattery 10, wire 1'1 leverli wires 12' and 13, winding of the indicating relay IR, line wire 14, contact 1 5-011 the west-bound signal MW, wire 16,. front contact 1'? of the track relay T wire 18',

switch box contact 19, wire 20, front contact '21- ofithe track relay T wire 22, winding of the control relay 1-Z',wire 23-, switchbox contact 24, wi re'25, front contact 26'of the-track relay T, wire 27, common return wire C to the negative terminal of battery 10. Under this assumed condition of the various track relays and switch box contacts in the circuit just traced, the control relay lZ will assume' its energized position. With the control relay 1Z assuming its energized position,

the; main sign alTM E" isfree to assume its proceed position, providing traflic conditions in advance thereof are clear; In this connection may be pointed out that" the circuit just traced in itself checks tra-fii'c conditions to the next opposing signal in ad- Vance, but in some cases the signal ME, may if d'esired, be prevented from assuming its proceed position becausethere is another train? in the next section ahead of the track section (3 by the inclusion of suitable sig rial blade or line relay" contacts in said'circuit. With the circuit through the control relay'l-Z closed, this on the assumption" that there-is-no conflicting rout'eset' up, the indicating relay lR" will assume its energized position, thereby closing an energizing circuit through the indicating lamp me, which circuit includes the front contact 30 of" the indicating relay 1R.

Should now an east-bound train accept the signal ME in its proceed position, and should it move into the track section A the track relay T would assume its de-energized position, thereby breaking the energizing circuit for the relay lZ at the contact 26 of the track relay T, and in turn affect de-energization of the indicating relay 2B and extinguishment of the indicating lamp ME. Similarly, occupancy of the track sections B and C will effect. extinguishment of the indicating lamp ME through the mediumof the opening of contacts 21 and 17 of these relays. The operator will thus be informed. of, the entrance of the train into the section of track A, B, and G.

Let us now assume that the operator returns the lever L back to its normal position, and; through. the? medium of a large lever, (not shown) which acts through mechanica means tooperate the track switch S operates the switch S tothe take-siding position. Under this condition the signal ME cannot be cleared because the switch box contact 24; now assumes the dotted position. and the circuit for the control relay 1Z for this reason cannot be completed.

Let us nowassume that the operator'moves the lever L to its dotted position'. Under this; condition the following circuit is closed provided the track section E and the fouling track circuit A is not occupied by another trainz-heginning at the battery 10, wires 11' and 35, lever If, wires 36 and 37, winding of the indicating relay 2R, wire 38-, front contact 39 of the track relay T wire 40, winding of the relay QZ, wire 41', switch box contact 24, wire 25, front contact 2(5- of the track relay T, wire 27:, and common return wire C to the negative terminal of battery 10. With the control relay 2Z assuming its energized position, due to completion of this circuit the dwarf signal DE will assume the proceed position through the medium of the front contact 4 5 of the control relay 2Z.. I't isthus-seenthat the dwarf signal DE cannot assume-its'proceed position unless the track switch S is in the, take-siding position and the track relaysT and T are in their energized position.

' Should either the track switch E or the fouling track circuit A; be. occupied at the time that the operator moves his lever L he will be informed of that fact by reason of failure of the indicating lamp DE to be illuminated, it being understood that with energizing current for the control relay 92 actually flowing through indicating relay 2R connected: in series therewith, will. also assume its energized position, and will illuminate the indicating lamp DE through a'ci'rcuit including the front contact e16 of the indicating relay 2R. Although the track switches S and S have been assumed to'be operable from the tower mechanically,

lever.

these track switches may be operated by switch machines protected against dangerous operation by approach locking circuits and detector lockingcircuits, all in a manner as described in detail in myv prior application Ser. No. 120,423, filed July 3, 1926', to which reference may be had, if desired. 1 Y

Applicant has thus provided an interlocking systemin which all of the features of interlocking are located locally with respect to the traflic controlling devices, and in which the control levers are free to be moved at any time, and in any manner, the entire protection against operating traffic controlling devices to positions conflicting with routes then set up being taken care of by local interlocking circuits including contacts of conflictable traffic controlling devices. Further, the system proposed indicates to the operator that a. certain route cannot be set up in the event that such is the case, by failure of the indicating lamp on theminiature track layout to be illuminated in response to movement of the corresponding Also, these same indicating lamps inform the operator of the passage of a train over the routeset up, in thatthey indicate when the signal at the entrance to such route assumes its danger position in response to the movement of trains into such route.

Having thus shown and described one rather specific embodiment of the present invention, it is desired to be understood that the particular embodiment illustrated has been shown for the purpose of exemplifying the invention and facilitating description thereof, and has not been selected for the purpose of showing the exact construction and circuit arrangement preferably employed in practicing the same, and that various changes, modifications and additions may be made to adapt the invention to any particular track layout to which the invention is to be applied, all without departing from r the spirit or scope of the invention, or the idea of means underlying the same, except as demanded by the scope of the following claims. v

\Vhat I claim as new is 1. In an interlocking system, the combination with a plurality of levers in an interlocking tower free to be moved to any posi tion at any time, a trafflc controlling device for eachlever controlled by suchlever and located at a distant way station, and a circuit controlled by oneof said levers for controlling a particular traffic controlling device including contacts mechanically operated by other and conflicting traffic controlling devices closed only when such other.

conflicting traffic controlling devices" are in their IlOIl-COIlfliOtlIlg positions;

2. In an interlocking system, the combination'with a plurality of levers in an interlocking tower free to be moved to any position at any time, a traflio controlling device for each lever controlled by such lever and located at a distant way station, a. circuit controlled by one of said levers for controlling a particular traflic controlling device including contacts mechanically operated by other and conflicting controlling devices tion at anytime, a traffic controlling device for each lever controlled by such lever and located at a distant way station, a control relay associated with each traflic controlling device for controlling the operative condition of such device, and a circuitcontrolled by one of said levers for a particular control relay including contacts mechanically operated by other and conflicting traffic controlling devices closed'only when such conflicting traffic col'itrolling devices are in their non-conflicting positions.

4. In an interlockin system, the combination with a plurality of levers in an interlocking tower free to be moved to any position at any time, a trafiic controlling device for each lever contr lled by such lever and located at a distant way station, a control relay associated with each trafiic controlling device for controlling the operative condition of such device, a circuit controlled by one of said levers for a particular control relay including contacts mechanically operated by other and conflicting traffic controlling devices closed only when such conflicting traflic controlling devices are in their non-conflicting positions, and means in said interlocking tower for indicating the continuity of said circuit.

5. In an interlocking system, the combination with a plurality of levers in an interlocking tower free to be moved to any position at any time, a traffic controlling device for each lever controlled by such lever and located at a distant way station, a control relay associated with each traflic controlling device for controlling the operative condition of such device, a circuit controlled by one of said levers for a particular control relay including contacts mechanically operated by otherand conflicting traffic controlling devices closed only when such conflicting traffic controlling devices are in their nonconflicting positions, an indicating relay in said interlocking tower included in series in said circuit and assuming its attracted positionwhen said circuit is energized, and an indicator controlled by said indicating relay and rendered active when said indicating relay assumes its attracted position.

6. In an interlocking syste1n,the scombiznation with a plurality :of levers in an interlocking tower tree to be moved to any position at any time, a traiiic-controlling device "for each lever controlled by such lever and located at a distant way station, and a circuit controlled by one o'fsaid leversio-r controlling a particular traflic controlling device including contacts controlled by other and conflicting trailic controlling devices closed only when such other conflicting traffic controlling devices are in their non-conflictingpositions. r

7. In an interlocking system, the combination with a plurality of levers in an interlocking tower free to be moved 'to any position .at any time, a traflic controlling device for each lever controlled by "such lever and located .at a distant'way station, "a circuit controlled by one of said levers'for controlling a particular traffic controlling device including contacts controlled by other and conflicting traiiic controlling devices closed only when-such other conflicting traffic controlling devices are in their nonconflicting positions, and means in said interlocking tower for indicating the continuity of said circuit.

8. In an interlocking system, the combination with .a plurality of levers .in an interlocking'tower free to be moved to'any position at any time, a trafllc controlling device for each lever controlled by such lever and located at a distant way station, a control relay associated with each traflic controlling device for controlling the operative condition of such device and a circuit controlled by one of said levers :for a particular control relay includingcontacts controlled by other and conflicting trafiic controlling devices closed only when such conflicting trailic controlling devices are in their nonconflicting positions.

9. In an interlocking system, the combination with a plurality of levers in an interlockin tower free to be moved'to an o- -relay including contacts associated with controlling devices are in other and conflicting trallic controlling clevices closed only when such conflicting trafiic their non-conflictin said interlockthe continuity of ing positions, and means ing tower for indicating said circuit.

10. In an interlocking system, the combination with a plurahty of levers in an in- "and located at :a distant way station, a con- :trol relay associated with each traflic controlling device for :controlling the operative condition of such device, a "circuit controlled by :one of said levers fora particularcontrol relay including contacts associated with other and conflicting trailic controlling devices closed only when such conflicting traific controlling devices are in their non- .confiicting positions, an indicating relay in said interlocking tower included in series in said circuitand assuming its attracted position when said circuit is. energized, and an indicator controlled by said indicating relay and rendered active when said indicating relay assumes its attracted position.

.11. In an interlocking system, the combination with a plurality of levers in an interlocking 'towerlfree to be moved to any position at anytime, a trafiic controlling device for each lever controlled by such lever and located at a distant way station, a control relay associated with each traflic controlling device for controllingthe operative condition of such device, and a circuit controlled by one of said levers for a particular control relay including contacts governed by other and conflicting trafiic controlling devices closed only when such conflicting tral'llc controlling devices :are in their non-conflicting positions.

12. In an interlocking system, the combination with a plurality of levers in an interlocking tower .free to :be moved to any position at any time, a wayside signal for a particular lever and located at a distant way station, a circuit controlled by said particular lever for controlling said signal and including a contact control-led in accordance with the position of a track switch in advance of said signal and closed only if said track switchis in a non-conflicting position.

'13.In an interlocking system, the combination with a plurality of levers in an interlocking tower free to be moved to any position at any time, a Wayside signal for a particu-lar lever and located at a distant way station, and a circuit controlled by saidparticular lever for controlling said signal and including a contact controlled in accordance with the position of atrack switch in advance of said signal and a contact controlled in accordance with the occupancy of the track ahead, said contacts being closed only if said track ahead is unoccupied and said track switch is in a non-conflicting position.

14. In an interlocking system, the combination with a plurality of levers in aninterlocking tower free to be moved to any pos-ition at any time, a wayside signal for a particular lever and located at a distant point, a track switch and anotherv signal ahead of said signal, anda circuit controlled by said particular lever for controlling said first mentionedv signal and including contacts controlled respectively in accordance with the position of said track switch and the position of said another signal in advance, said contacts being closed only if said another signal in advance is at proceed and said track switch is in a non-conflicting position.

In testimony whereof I affix my signature.

SEDGWICK N. WIGHT. 

